This invention relates to a novel fitting for the end of a fuel tank filler tube such as, for example, a fuel tank filler tube of an automotive vehicle.
Government restrictions on the use of leaded fuels have lead to the use of restrictor assemblies in fuel tank filler tubes, generally in the end of the filler tube remote from the fuel tank. Restrictor assemblies are designed to allow insertion into the filler tube of a nozzle of the size employed with unleaded fuel delivery systems, but prevent the insertion into the filler tube of the larger size nozzles used for leaded fuel delivery systems. Various multi-piece restrictor assemblies are known. These, however, typically comprise a large number of parts, resulting in cost disadvantages both in manufacture and assembly. In addition, known restrictor assemblies typically are fabricated at least in part from ferrous or other metals suitable for welding, since restrictor assemblies are most often welded into position for use. The use of such metals results in a relatively heavy assembly and may require costly corrosion protection.
While fuel tank filler tubes have in the past generally been fabricated from ferrous metals, there is presently a trend toward the substitution of synthethic material parts for metal parts. Considerable weight advantage can result which, in the case of automotive vehicles, can lead to improved fuel economy. Exemplary of this trend is the use of plastic, blow molded fuel tank filler tubes. A restrictor assembly suitable for use with such blow molded filler tubes is required.
It is an object of the present invention to provide a restrictor assembly suitable for use with a blow molded synthetic material fuel tank filler tube.
It is a further object of the invention to provide a restrictor assembly which requires few parts, each of which can be fabricated of inexpensive, light weight, corrosion resistant synthetic materials.
It is a further object of the invention to provide a restrictor assembly which can easily be assembled and fitted into a fuel tank filler tube and which, without welding, adhesive or other extraneous attachment means, can provide a positive, fixed engagement between the restrictor assembly and the filler tube to assure against pull-out of the restrictor assembly from the end of the filler tube.
It is a further object of the invention to provide a restrictor assembly to which a closure cap for the filler tube can be mounted to seal the filler tube.
These and other objects and advantages will be evident from the following description of the invention.